非常规/复杂油藏

米德兰的石油生产商正在研究下一个二叠纪

二叠纪生产商正在寻找新的地点和方法来维持这个巨大盆地的生产。

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一代又一代的井覆盖了二叠纪,预计将出现新一波浪潮。
资料来源:斯蒂芬·拉森福斯

当米德兰石油会议上主题演讲的标题是“寻找下一个二叠纪盆地的秘密”时,这表明有人对现状表示怀疑。

今年该地区的非常规石油产量约为 570 万桶/日,市中心一家银行的视频板显示,随着价格上涨至近 100 美元/桶,今年二叠纪钻井平台数量有所下降。

最近举行的SPE 二叠纪盆地能源会议上的发言者乐观地关注维持高产量和高利润率所需的变革。

Diamondback Energy 地球科学与技术高级副总裁戴夫·坎农 (Dave Cannon) 表示,近年来,产量最高的一级钻探场地的库存正在减少,而这些钻探台近年来提供了大部分产量。他问道:“10 年后,下一个 Tier 1 是什么?”

当主旨演讲人描述下一个二叠纪盆地时,德文能源公司执行副总裁兼首席运营官克莱·加斯帕 (Clay Gaspar) 表示,“我们现在就站在这个立场上。”

富含石油和天然气的岩石已经存在,但要避免过去十年页岩气繁荣之前的 50 年衰退重演,需要在石油勘探、开发和生产以及开发新区域方面采取渐进式改进措施由于大规模开发限制了 Wolfcamp 和 Spraberry 地层新井的产量。

生产商正在研究如何最大限度地提高这些层中剩余油井的生产率,这是相当可观的。

康菲石油公司 (ConocoPhillips) 报告了一项大规模开发项目,该公司目前正在 2×3 英里长的场地狭窄端排列的钻井平台上钻 44 口井。很快,当五台钻机的钻井工作接近尾声时,压裂作业就会开始。

满足租赁义务所需的高井数也是对他们在所有井同时启动时能否最大化产量的考验。

如果按计划进行,任何一口井的产量都不会因为附近的旧井而减少。与过去使用巨型垫的经验(结果令人失望)不同,与正常尺寸的垫相比,间距并没有被压缩。

这也是电动钻井和现场处理现场气体以用于动力压裂等新方法的试验场。

这不是康菲石油公司剩下的唯一大型区块,但拥有如此大的工作空间已成为一种有限的商品。

加密钻探已成为常态,而且一直如此;在老母井附近添加的新井产量不高。

Goehring & Rozencwajg Natural Resource Investors 的一项研究预测,二叠纪产量很快就会达到顶峰,这在很大程度上要归功于加密钻探的高水平。

“2012 年,我们估计三个重要页岩盆地中钻探的井中只有 30% 是“儿童井”。到 2022 年,这一数字已达到 85%。该顾问的报告称,在一级地区,目前所有油井均未完工,产能低于预期。

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米德兰市中心一家银行外的标牌上可以追踪二叠纪的生命体征。
资料来源:斯蒂芬·拉森福斯

解决难题

其他来源,包括 Enverus 和美国地质调查局,对剩余可钻探面积的估计要高得多,但那里的大公司谈到了寻找新生产视野的努力。他们有一些想法,但此时还有一些难题需要解决。

“根据目前的方法,我们未来将开发的一些资源并不被视为现在的资源,”加斯珀说。

一些新产品将使用新方法从老井中流出,例如对二叠纪老井进行重复压裂,以及探索新的地平线,例如上斯普拉贝里和巴尼特页岩。

在这两个区域均已钻出良好的油井。坎农说,它们“开始着火了。”但在这个早期阶段,这有点像点燃湿木头。

“Upper Spraberry 正在接受测试。它要复杂得多,生产结果的分布也更广泛。这是地下谈话,”坎农说。

根据 Rystad Energy 最近的一份报告,Elevation Resources 已在中央盆地平台的 Barnett 成功钻探油井,而西方石油公司已将其 Barnett 测试井从 2021 年的两口增加到今年在米德兰盆地的 12 口。

该研究还指出了 APA Corp. 在 2019 年的 Barnett 发现,该发现最初看起来像是一个大型石油发现,但事实证明主要是天然气。事实上,随着二叠纪产油井的老化,它们倾向于全天然气生产,这意味着只需付出很少的努力就能确保下一个二叠纪将成为一个强大的天然气生产国。

Enverus 的一份描述该盆地生产区的报告称,上斯普拉贝里层是斯普拉贝里层中“最经证实的”。据称,巴尼特是由三个长凳组成的一组的一部分,这些长凳“结构复杂,断层和侵蚀程度很高”。

采用新方法从老油井中获取更多资源也是该计划的一部分。

如果大量的税收抵免能够产生大量从烟囱和大气中捕获的CO 2 ,​​那么这可能会创造扩大提高石油采收率的机会。这将为留在地下的天然气赢得信用,但公众的利益一直在于长期封存,这受益于更大的税收减免。

原因之一是注入裂隙超致密岩石带来的问题多于机遇。

雪佛龙提交的两篇论文表明,它能够利用注气来增加注入井附近多口井的石油产量。收益并不大,但表明二叠纪盆地的一家大型石油公司正在投入大量资源支持非常规 EOR 方案,逐口使用吞吐方法。

坎农说,2013 年之前完工的油井的潜力“实际上没有受到影响,位于管道后面”,并补充道,“我们必须投资新技术才能使其发挥作用。”

他和小组中的其他人在谈论对这些老井进行重复压裂以寻找二叠纪未受刺激的岩石时使用了将来时。

德文郡已经表明,可以将 Eagle Ford 未完工的老油井的产量从 5% 提高到 15% 左右,但在二叠纪尚无法实现。

“到年底,我们将在地面进行 50 处折射,还有 100 处正在设计中,”加斯帕说。但他警告说,这仅限于井组间距较宽(例如 60 英尺)且状况相对良好的老井。

虽然他们正在评估 500 多口井,但许多井都未能通过。那些这样做的人将“不存在机械问题”,这些问题可能会干扰衬管的运行以覆盖旧的穿孔或可能限制其安全泵送作业能力的问题。

到目前为止,重复压裂测试已经在 Eagle Ford 进行,该地区的产油区面积已大部分被钻探。没有采取同样措施的原因包括对未知事物的恐惧,以及缺乏数据表明重复压裂是二叠纪盆地新油井开发的一个有竞争力的选择,而二叠纪盆地仍有可用面积。

即使有所有这些想法和更多想法,新井也很难跟上快速下降的旧井的速度,但会议上没有人表示他们怀疑二叠纪还有另一个生命。

康菲石油公司米德兰盆地副总裁尼克·麦肯纳 (Nick McKenna) 解释了这种信心:“永远不要对创新下赌注。”

原文链接/jpt
Unconventional/complex reservoirs

Oil Producers in Midland Are Working on the Next Permian

Permian producers are looking for new places and ways to sustain production in the giant basin.

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Generations of wells cover the Permian, and a new wave is expected.
Source: Stephen Rassenfoss

When the title of the keynote address at an oil conference in Midland is “The Secret To Finding the Next Permian,” it suggests there are people with doubts about the status quo.

Unconventional oil production there has been around 5.7 million B/D this year, and the video board at a downtown bank was showing the drop in the Permian rig count this year as prices have risen to nearly $100/bbl.

Speakers at the recent SPE Permian Basin Energy Conference were optimistically focused on the changes needed to sustain that high output and high profit margins as well.

The inventory of the most productive, Tier 1 drilling sites is dwindling for the benches that have delivered much of the production in recent years, said Dave Cannon, senior vice president of geoscience and technology for Diamondback Energy. He asked, “What is the next Tier 1 out there 10 years from now?”

When it came time for the keynote speaker to describe the next Permian, Clay Gaspar, executive vice president and chief operating officer for Devon Energy, said, “We are standing on it now.”

The oil- and gas-rich rock is there but avoiding a repeat of the 50-year slump that preceded the shale boom over the past decade will require a combination of incremental improvements in finding, developing, and producing oil, as well developing new zones as intense development crimps production of new wells in the Wolfcamp and Spraberry formations.

Producers are working on ways to maximize well productivity in what is left in those layers, which is considerable.

ConocoPhillips reported on a massive development where it is now drilling 44 wells, from pads lined up at the narrow ends of the 2×3-mile-long site. Soon, when the five rigs near the end of the drilling jobs, fracturing will begin.

The high well count, which is needed to satisfy lease obligations, is also a test of whether they can maximize production when all wells start up at the same time,

If it works as planned, none of the wells will have their production reduced by an older well nearby. And unlike past experiences with megapads, which delivered disappointing results, the spacing isn’t compressed compared to normal sized pads.

This is also a test site for new methods such as electric-powered drilling and the processing of field gas on site so that it can be used to power fracturing.

This isn’t the only large-sized block left for ConocoPhillips but having that much space to work has become a limited commodity.

Infill drilling has become the norm, and as has always been the case; new wells added near older parent wells are not as productive.

A study by Goehring & Rozencwajg Natural Resource Investors predicted that Permian production would peak soon, due in large part to the high level of infill drilling.

“In 2012 we estimate that only 30% of wells drilled in the three significant shale basins were ‘children.’ By 2022, that figure had reached 85%. In Tier 1 areas, effectively, all current wells are children, with lower-than-expected productivity,” the consultant’s report said.

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The Permian’s vital signs are tracked on a sign outside a bank in downtown Midland.
Source: Stephen Rassenfoss

Solving Puzzles

Other sources, including Enverus and the US Geological Survey, offer much higher estimates of the remaining drillable acreage, but the big companies there talked about the efforts to find new productive horizons. They have some ideas, but at this point there are puzzles to solve.

“Some of the resources we will develop in the future are not considered a resource now based on current methods,” Gasper said.

Some of what’s new will be flowing out of old wells using new methods, such as refracturing old wells in the Permian and exploring new horizons such as the upper Spraberry and the Barnett Shale.

In both those plays good wells have been drilled. Cannon said they “are starting to catch fire.” But at this early stage, it is a bit like lighting wet wood.

“The Upper Spraberry is being tested. It is dramatically more complex, with a much wider distribution of production results. That is the subsurface talking,” Cannon said.

Elevation Resources has been successfully drilling oil wells in the Barnett in the Central Basin Platform, and Occidental has increased its Barnett testing from two wells in 2021 to 12 in the Midland Basin this year, according to a recent report from Rystad Energy.

That study also pointed out APA Corp.’s Barnett discovery in 2019, which initially looked like a big oil find but proved to be mostly gas. The fact that as Permian oil-producing wells age, they tilt toward all-gas production means that little effort will be required to ensure the next Permian will be a robust gas producer.

A report from Enverus describing productive zones in the basin said the Upper Spraberry is the “least proven” of the Spraberry layers. It said the Barnett is part of a group of three benches that are “structurally complex with a high degree of faulting and erosion.”

Employing new methods for getting more from older wells is also part of the plan.

If massive tax credits are able to create a large supply of CO2 captured from smokestacks and the atmosphere, that could create opportunities to expand enhanced oil recovery. That would earn credits for gas that remained in the ground, but the public’s interest has been on long-term sequestration, which benefits from a larger tax break.

One reason for that is that injecting into fractured ultratight rock has presented more problems than opportunities.

Chevron presented two papers that showed it was able to use gas injection to increase the oil production on multiple wells near an injection well. The gains were not large, but showed a major oil company in the Permian is putting serious resources behind an unconventional EOR option, using huff-n-puff methods well by well.

And there’s potential in wells completed before 2013 that “is literally untouched, sitting behind the pipe,” Cannon said, adding, “We have to invest in new technology to make it effective.”

He and others on the panel used the future tense when talking about refracturing those older wells to go after the rock not stimulated in the Permian.

Devon has shown it is possible to increase yields on badly completed old wells in the Eagle Ford to around 15% from 5%, but not yet in the Permian.

“By year-end we will have 50 refracs in the ground, with several 100 more on the drawing board” Gaspar said. But he cautioned that this is limited to older wells with wide cluster spacing—60 ft for example—in relatively good condition.

While they are evaluating more than 500 wells, many will not make the cut. Those that do will be “without mechanical issues” that can interfere with running a liner to cover old perforations or problems that could limit their ability to safely pump the job.

So far, refracturing testing has been done in the Eagle Ford where acreage in oil-producing zones has largely been drilled out. Reasons offered for not doing the same range from fear of the unknown to a lack of data showing refracs as a competitive option to new well development in the Permian where acreage remains available.

Even with all those ideas and more, it will be difficult for new wells to keep up with rapidly declining older wells, but nobody at the conference said they doubted the Permian has another life left in it.

Nick McKenna, vice president of Midland Basin for ConocoPhillips, explained that confidence: “Never bet against innovation.”